External Breakers; Grounding Wire - Toshiba 4300 series Installation And Operation Manual

9.4

External Breakers

The UPS is not equipped with isolation circuit breakers. Qualified personnel should provide the external
breakers for the AC input/output, bypass input and DC input.
See Figure 11.1 – External Wiring Diagram, for the circuit position of the breakers.
Table 11.7 shows the minimum external breaker rating for each UPS. The bypass, input and output require
3-pole breakers.
C R
apaCity ated
O
utput
30 kVA 208/120 V
50 kVA 208/120 V
9.5

Grounding Wire

Be sure to ground the UPS as specified.
Using the UPS without a proper ground will deteriorate the insulation,
cause leakage of currents and electric shock. The resistance to
ground should be less than or equal to 10 ohms.
The earth grounding bus is located inside, at the bottom-front of the unit. See Section 8.5 - Parts
identification.
Use a AWG 2 (or 38 mm
grounding wire. Run the grounding wire through the
opening at the bottom, or through a hole in the top
knockout plate or through the side access hole. See
Figure 9.5 Connect either the earth ground bus to the
grounding wire.
The ground wire must have a crimp terminal with a 1/2
in. (12 mm) diameter bolt hole. The ground bus has
33/64 in. (13 mm) bolt holes. The connect the crimp
terminal and ground bus together using a 7/16 in. (10
mm) diameter bolt.
26
TABLE 9.2 UPS MINIMUM DEVICE RATINGS
i B O
nput ReakeR
R B
ating ReakeR
208 V – 125 A 208 V – 110 A
208 V – 200 A 208 V – 175 A
WARNING
) or larger cable for the
2
/B dC i
utput ypass nput
R
ating
400 VDC – 150 A
400 VDC – 250 A
FIGURE 9.5 - UPS GROUND BUS
4300 Series Installation and Operation Manual
B R
ReakeR ating
B
atteRy